I suggest you ...

Space restriction

The sudden decision of reducing the space from 50GB to just 5GB was totally unprofessional and not customer oriented. If from the very beginning the space granted would have been 5GB, then there would have been no issues, but just taking a drastic step and reducing the space is not the right thing to do. When a customer relies on this space and uses this app by putting all his large size important data in it and then, if he has to remove the data due to space constraints- then one would not be able to rely on any Microsoft apps, it being totally unreliable !!